WASHINGTON – The Washington Suburban Sanitary Commission says repair crews plan to remove a 20-foot section of a 5-foot pipe Wednesday night and replace it with a new pipe.

Once the replacement is complete, crews will need several more days to wrap up work along Connecticut Avenue between Dunlop Street and Manor Road, according to WSSC.

Two northbound lanes of Connecticut Avenue have reopened to traffic. All southbound lanes remain open.

EARLIER – Wednesday – 3/20/2013, 9:59am ET

CHEVY CHASE, Md. – A flurry of construction activity surrounds the intersection in Chevy Chase where a water main burst Monday.

Workers are repairing damage after the break blasted a giant crater in the ground.

The cause is still under investigation.

According to the Washington Suburban Sanitary Commission, it may take several months to determine exactly why the break happened.

Utility officials say they never received warning signals from an expensive piece of equipment installed at the site, The Washington Post reports.

The automatic sensor is programmed to detect weaknesses around the pipe and notify the utility company so it can be shut down before a break occurs. WSSC tells The Post it doesn’t know why the the sensor did not ping.

The tool is part of a broader detection system that WSSC has spent more than $20 million on since 2007.

Near the water main break site, only one lane of northbound traffic on Connecticut Avenue gets by between East-West Highway/Md. 410 and Jones Bridge Road.

As WSSC crews work there, crews also are on the scene of another water main break. A 10-inch water main broke at the corner of Willard and North Park avenues in the Chevy Chase area Wednesday morning. Just before 10 a.m., a WSSC spokesperson said three high-rise buildings are without water. It could take four- to six hours to make the repairs.